| 双极膜电渗析解离NaCl清洁制备酸碱的实验研究 |
| 作者: 1 南开大学 环境科学与工程学院,天津,300071 |
| 单位: 1 南开大学 环境科学与工程学院,天津,300071 |
| 关键词: 双极膜;电渗析;氢氧化钠;盐酸 |
| DOI号: |
| 分类号: TQ028.8 |
| 出版年,卷(期):页码: 2014, 34(3):96-103 |
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摘要: |
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采用国产双极膜、均相阴、阳离子交换膜交替排列构成的三隔室双极膜电渗析(BMED)构型,以NaCl为原料制备NaOH和HCl。研究了电流密度、原料液浓度和电极液浓度对BMED操作性能的影响,并对两种不同的均相阳膜进行了对比考察。结果表明:在电流密30 mA?cm-2, NaCl原料液浓度为1.5 mol?L-1的条件下,实验考察的220 min内NaOH的收率可达80.19 %,其收率和能耗随电流密度的增大而增加;电流密度恒定时,较高的原料液浓度利于保持更小的膜堆电阻,过程能耗相应降低;本实验条件下,极室Na2SO4的浓度在1 %~2 %的低浓度范围内效果优于3 %~4 %的高浓度范围。实验进一步采用向原料室持续补充10 % NaCl的操作,5 h后产品NaOH浓度可达10 %左右,其浓度是一次性添加原料操作时得到的2.5倍。 |
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A bipolar membrane electrodialysis (BMED) stack with three compartments was adopted to directly produce sodium hydroxide and hydrochloric acid by sodium chloride splitting. Effects of current density, feed concentration and electrode compartment concentration on the BMED performances were well investigated. Also the influences of two different kinds of cation-exchange membranes were compared with each other. The results exhibited that with current density of 30 mA?cm-2 and 1.5 mol?L-1 NaCl solution, the conversion rate of NaOH could achieve 80.19 % in 220 min. The conversion rate and energy consumption increased as the current density increased. At the constant current density, the resistance of the stack reduced as NaCl concentration increased, and the energy consumption reduced accordingly. The concentration of electrode compartment with low concentration (1 %~2 %) was better than high concentration (3 %~4 %) in this condition. Furthermore, 10 % NaCl was supplied to the feed compartment continually, the concentration of product NaOH can reach 10 %, which was 2.5 times compared with the one-time addition of NaCl. |
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基金项目: |
| 天津市科技兴海专项资金(KJXH2011-007)及海洋公益性行业科研专项经费项目(201405008)资助; |
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作者简介: |
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A bipolar membrane electrodialysis (BMED) stack with three compartments was adopted to directly produce sodium hydroxide and hydrochloric acid by sodium chloride splitting. Effects of current density, feed concentration and electrode compartment concentration on the BMED performances were well investigated. Also the influences of two different kinds of cation-exchange membranes were compared with each other. The results exhibited that with current density of 30 mA?cm-2 and 1.5 mol?L-1 NaCl solution, the conversion rate of NaOH could achieve 80.19 % in 220 min. The conversion rate and energy consumption increased as the current density increased. At the constant current density, the resistance of the stack reduced as NaCl concentration increased, and the energy consumption reduced accordingly. The concentration of electrode compartment with low concentration (1 %~2 %) was better than high concentration (3 %~4 %) in this condition. Furthermore, 10 % NaCl was supplied to the feed compartment continually, the concentration of product NaOH can reach 10 %, which was 2.5 times compared with the one-time addition of NaCl. |
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参考文献: |
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[1] 徐铜文,汪志武. 双极膜的理论及应用展望[J]. 水处理技术,1998,24(1):20-25. |
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